I can't remember anymore what I tried and what I didn't :) At the end, I mostly tried not to bang my head against the wall.

Anyway, even your second link stresses: "The primary IDE recommendation is IntelliJ, not Android Studio nor Eclipse". My IDE of choice is Android Studio, and it not being particularly recommended is a red light to me already. Maybe I'm just traumatized.

I'm surely lazy. I wish Google made Scala support for Android official and integrated it seamlessly.